Field Measurement of the Corrosion Rate of Steel in Concrete using a Microprocessor Controlled Unit with a Monitored Guard Ring for Signal Confinement

2009 ◽  
pp. 91-91-16 ◽  
Author(s):  
JP Broomfield
Keyword(s):  
Corrosion Rate ◽  
Field Measurement ◽  
Guard Ring

scholarly journals Propagation of reinforcement corrosion: principles, testing and modelling

2018 ◽  
Vol 52 (1) ◽  
Author(s):  
Carmen Andrade
Keyword(s):  
Corrosion Rate ◽  
Large Scale ◽  
Galvanic Corrosion ◽  
Steel Corrosion ◽  
Electrical Signal ◽  
Guard Ring ◽  
Concrete Durability ◽  
Reinforcement Corrosion ◽  
Chloride Threshold ◽  
Corrosion Zone

Abstract Reinforcement corrosion is the risk most frequently cited to justify concrete durability research. The number of studies specifically devoted to corrosion propagation, once the object of most specialised papers, has declined substantially in recent years, whilst the number addressing initiation, particularly where induced by chlorides, has risen sharply. This article briefly describes the characteristics of steel corrosion in concrete that need to be stressed to dispel certain misconceptions, such as the belief that the corrosion zone is a pure anode. That is in fact seldom the case and as the zone is also affected by microcells, galvanic corrosion accounts for only a fraction of the corrosion rate. The role of oxygen in initiating corrosion, the scant amount required and why corrosion can progress in its absence are also discussed. Another feature addressed is the dependence of the chloride threshold on medium pH and the buffering capacity of the cement, since corrosion begins with acidification. Those general notions are followed by a review of the techniques for measuring corrosion, in particular polarisation resistance, which has proved to be imperative for establishing the processes involved. The inability to ascertain the area affected when an electrical signal is applied to large-scale elements is described, along with the concomitant need to use a guard ring to confine the current or deploy the potential attenuation method. The reason that measurement with contactless inductive techniques is not yet possible (because the area affected cannot be determined) is discussed. The method for integrating corrosion rate over time to find cumulative corrosion, P corr, is explained, together with its use to formulate the mathematical expressions for the propagation period. The article concludes with three examples of how to use corrosion rate to assess cathodic protection, new low-clinker cements or determine the chloride threshold with an integral accelerated service life method.

The Study to the Corrosion of Reinforcing Steel in Concrete by Using Galvanostatic Pulse Technique

2014 ◽  
Vol 501-504 ◽  
pp. 916-919
Author(s):  
Yan Tao Dou ◽  
Bao Hong Hao ◽  
Bo Meng ◽  
Jun Xie ◽  
Ming Liang Dong ◽  
...  
Keyword(s):  
Reinforced Concrete ◽  
Corrosion Rate ◽  
Current Pulse ◽  
Field Measurement ◽  
Concrete Cover ◽  
Pulse Technique ◽  
Linear Rule ◽  
Standard Specimens ◽  
Different Thickness ◽  
Made In

This paper presents the result from a study of Galvanostatic Pulse Technique for determining the corrosion rate of steel in reinforced concrete. The investigation to the condition factors and instrument parameter that significantly influence the testing result of the current pulse technique in on-site measurements is made in this paper. Firstly standard specimens which have different thickness of concrete cover and NaCl adding content were prepared, and instruments (CorroMap TM) for field measurement of corrosion rate of steel in reinforced concrete are selected for testing. From the study we can conclude that Icorr increased with the decreasing of the thickness of the concrete cover and the adding content of NaCl to the concrete when casting with non-linear rule, and an anodic pulse of 50 μA with pulse duration of 10 seconds is appropriate for testing both passive and active area of rebar.

Effects of Particle Size Distribution on Corrosion Rate of Carbon Steel in Soil

2020 ◽  
Vol 69 (4) ◽  
pp. 102-106
Author(s):  
Shota Ohki ◽  
Shingo Mineta ◽  
Mamoru Mizunuma ◽  
Soichi Oka ◽  
Masayuki Tsuda
Keyword(s):  
Particle Size ◽  
Carbon Steel ◽  
Corrosion Rate ◽  
Particle Size Distribution ◽  
Size Distribution
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